diff --git a/src/org/pEp/jniadapter/AbstractEngine.java b/src/org/pEp/jniadapter/AbstractEngine.java
index 1242ff9..57ef25e 100644
--- a/src/org/pEp/jniadapter/AbstractEngine.java
+++ b/src/org/pEp/jniadapter/AbstractEngine.java
@@ -24,7 +24,9 @@ abstract class AbstractEngine implements AutoCloseable {
     }
 
     public AbstractEngine() throws pEpException {
-        init();
+        synchronized (AbstractEngine.class) {
+            init();
+        }
     }
 
     final public void close() {